You are right in that evdev does manage HID devices by itself. I put in my make.conf

Code:

INPUT_DEVICES="evdev synaptics joystick"

because I was having problems getting my joystick to work as a joystick instead of it being registered as a mouse. I'm not sure if this is the correct way to get it to work but it helped me. Maybe someone with more knowledge than me can help explain this because I'll be the first to admit that I don't really know all that much about gentoo after being away for about 5 years lol.

The first condition basically means as long as your device support ABS_X (there are of course some trivial condition in joydev_match() to exclude touchpads) the kernel will register it to an joystick device. I guess you can try to unload other modules like mouse.ko to make sure the problem is in the joystick detection part. If it is still not solved I guess depends on how strong is your motivation, you might want to add some debug code to the kernel to figure out why, it is going to be pretty straightforward but quite tedius. Also since your event8 looks healthy enough for a joystick, some newer version of your game might just use the evdev interface, as long as the permission allows (on my computer it seems all the eventX devices can only be read by root by default).

BTW, event7 the so called "PS2 generic mouse" sounds fishy, I doubt you use a logitech mouse, a touchpad and a ps2 mouse at the same time, you might want to figure out why it is there, it could be related to your trouble with joystick.

The only (minor) problem is this stick is recognized as both a Joystick and a mouse, so I have to unplug it when I leave the game otherwise the point become crazy.
I think it is also attached as "input0". Any way to backlist it or to make X ignore it ?